Modulating system



R. M. HEINTZ MODULATING SYSTEM Filed Dec.

Dec. 26, 1933.

, 1931 2 Sheets-Sheet l a mu M H P m P ATTORNEY Dec- 26, 1933- R. M. HEINTZ MODULATING SYSTEM Filed Dec. 21, 1931 2 Sheets-Sheet 2 I I 1 1 I INVENTOR, RALPH M. HE/NTZ.

A TTOR NE Y Patented Dec. 26,1933

Ralph M.

Heintz & Kaufman,

a corporation of Nevada Heintz, Palo Alto, Calif., assignor to Ltd., San Francisco, Calif.,

Application December '21, 1931 Serial N0. 582,275

'14 Claims. (01. 179-17 1) This invention relates to modulating systems, and particularly to systems for modulating the output of a-frequency multiplier or alternating current generator wherein a-beam of cathode rays is deflected across an anode having a plurality of openings therein, thus interrupting the direct current'comprising thebeam of rays and converting it into an alternating current. Frequency multipliers of this type are described in a copending application of A. H. Brolly, Serial No. 574,292 and in mycopending applications, Serial Nos. 574,260 and 574,262, all filed November 11,,

Among the objects of my invention are: To provide a method whereby an alternating current of relatively low power and low frequency may be modulated and simultaneously stepped up in both power and frequency .to' an alternating current ofrelatively high .power. and high frequency; to provide .a method and means of generating a polyphase modulated current; ,to provide a means .of; generating a modulated rotary-polarized radio wave; and :to providea means whereby apartially modulated wave of low frequency may be multiplied and amplified into .a fully modulated wave of relatively high frequency.

- Othertobjects of this invention will beapparent or will be specifically pointed. out in the descriptiori forming a part of this specification, but I do not limit myself to the embodimentof my invention herein described, as various forms may be adopted within'the scope .of theclaims.

Referring to the drawings:

Figure lis a diagram, largely schematic, illustrating a system for generating a three-phase modulated alternating current, and converting said current into a rotary-polarized radio wave.

Figure 2 isaa transverse sectionof one of the multiplying and modulating tubes, the-plane of projection being indicatedby the line 2-2 .of Figure -1. V.

V Figure 3 is a diagram illustratingthemodification required in the apparatus of Figure .1 in order togenerate the ordinary single phase plane polarized radio wave.

Figure 4 is an elevation-of the anode structure utilized intheapparatus of Figure 3, the plane of projection'being indicated by the line 4-4 of Figure '3. a

As indicated above, the,frequencyconverters or frequency multipliers here considered operate by deflecting a beam of cathode rays across an apertured anode'orsuccession'of anodes, so that the current carried-by the cathode ray beam is diverted successively into -a pluralityof paths, these said anodejpreferably to fallequally upon the from direct current into alternating current, thus {two stages, of frequency multiplication are used,

paths preferably comprising the successive phases of a polyphase circuit. a I v j Broadly considered, the modulating method of this invention comprises altering or varying the deflection of the beam, so that at .one extreme of the variation the path falls entirely .upon one of the anodes, while at the other extreme the beam passes intermittently through the apertures in other anodes if such are provided. II; the first case the cathode ray current forms a direct current flowing in one branch of the circuit. In the other case the current inthis path is completely interrupted when the beam passes through the apertures, the current passing in its entirety successively through the different phase branches of the circuit. In intermediatepositions of deflection more or less of the beam will be interrupted, to give varying percentages of conversion modulating the output of thedevice.

The preferred form of. my invention is shown in Figure 1. Inthe particulararrangement shown the second stage being modulated by the method of this invention. The first frequency multiplier, designed by the general reference character .1 comprises a tubularenvelope 2 provided with a stem 3 which carries an emitting cathode 4, which is raised to the proper temperatureby a heating. coil 5. The leads 6 of the coil connect to a battery or other suitable source 7.

Closely adjacent .to the cathode there is mounted an auxiliary anode comprising a disk 9 having a central aperture which is surrounded by a projecting collar 10. The anode lead v11 passes through the, stem and connects to an in-.

termediate point on a battery 12, so asto maintain the auxiliary anode at a positive, potential with respect to the cathode.

Mounted at the opposite .end of the tube are three anode disks. The foremost disk 14 is provided with sector-shaped openings 15, uniformly spaced around the anode. Each of these apertures is, double the width of the bars 16 between the apertures.

Behindthe first disk is the second disk l'l, which is also provided with apertures whichare preferably but half the width of the openings in the anode 14. One edge of eachof theapertures 19 in the anode 17 is alined with one edge of the apertures 15. The third disk 20 may be'unapertured. Since it is convenient to make the two I frequency multipliers similar, the anode .14 is'pro vided Witha relativelylarge central unapertured portion 21, the reason for which will be discussed in connection with the second multiplier tube.

The tube is preferably surrounded with a solenoid 22, which is shown schematically in Figure 1 and whose actual position is illustrated in Figure 2. A direct current from a source 24 is passed through this coil, this current being so adjusted that the beam of cathode rays reaches maximum concentration in the plane of the anode 14. Other means of focusing or concentrating the beam, which are well known in the art, may be used if desired.

Also surrounding the tube, in'planes parallel to the axis thereof, are three deflecting coils 25, 26 and 27. These coils are also illustrate sche matically in Figure 1, while their actual location is shown in Figure 2. The coils are connected in three-phase relation, either star or delta connection being satisfactory, and are excited by a threephase generator 29.

Leads 30, 31 and 32 connect from the anodes 14,. 17 and 20 respectively to the deflecting coils '25, 26 and 27' of a second frequency multiplier similar to that just described. These deflecting coils are preferably tuned by condensers 34, which areshown connected in delta to the starconnected deflecting coils. A lead 35 connects from the neutral of the deflecting. coil system to the filament 36 of a vacuum tube 37. The plate 38 of the tube connects to the positive terminal of the source 12.

' A'microphone L0, in series with a battery 41, is. connected to the primary 4.2 of a transformer whose secondary'd l is connected'between the grid 45 of the vacuum tube and the lead 35. A battery 46 beats the filament of the tube. This arrangement constitutes a modulating system for the output of the first frequencymultiplier tube, this system being described and claimed. in my copending application, Serial No. 582,274, filed simultaneously with this application.

The second frequency multiplier tube, which is indicated by the general reference character 47, being similar to the tube just described, will not be described in detail. The various parts of this tube are designated by the same reference is projected axially of the tube.

characters as those applied to similar parts of the tube 1, but distinguished by accents.

The anodes 14', 17' and 20 of the tube 4? connect to the three phases 50,51 and 52 respectively of a high frequency star connected transformer, which is tuned by the condensers 54. The secondary of this high frequency transformer, comprising the three coils 55, 56 and 5'7, excite the threephase antennasystem 59. The coupling between the primary and secondary coils is indicated by the bracket M. Various methods of spacing the radiating elements in the threephase antenna system'are described in my copending application, Serial No. 439,054, filed l are. accelerated by the auxiliary anode 9,

of them passing through the central aperture :1 the anode to form a pencil of cathode rays which These rays are concentrated or focused into a sharply defined beam by the magnetic field from the coil'22. The

voltage for accelerating the electrons is provided from the source 12.

. Three-phase current from the generator 29, flowing in the deflecting coils 25, 26 and 2'7, generates a rotating magnetic field transverse of the tube, which deflects the axial beam of electrons in a circular path. The beam of electronsthera .iore falls successively upon the anodes 14, 1'7

and 20, causing the anode current to flow successively in the three coils 25, 26 and 27. These coils being tuned by the condensers as, the harmonics due to the non-sinusoidal wave form of the interrupted current are largely smoothed out, so that a rotating magnetic field of higher frequency is generated by the deflecting coils 25', 26' and 27. Voice currents from the microphone 40 vary the potential of the grid 4.5 of the tube 37, whose plate circuit is in series with the three anodes of the first multiplying tube, thereby varying the intensity of the anode currents, thus modulating the deflecting field. of the tube 47. i v

The cathode ray beam in the tube 47 is also deflected in a circular path by the three-phase output of the first tube, and the diameter of this path varies with the intensity of the deflecting current. The traces of the beam on the anode, for various valuesof the deflecting field,.are indlcated by the three dotted circles 60, 61 and 62 of Figure 2. It will be seen'that when maximum current passes through the deflecting coils of the second tube the beam will be wholly interrupted, passing in its entirety to each of the successive anodes. When the modulation decreases the defiecting current, the beam will be less widely defiected, only a portion passing across the apertures 15, while when the deflecting current is at its minimum the trace of the beam will occupy the position indicated by the dotted circle 62, and will trace its circular path entirely upon the foremost anode 14' without interruption. In this inner position the output of the tube 47 will be a direct current flowing in the coil 50, while, in

the outermost position of the beam the current will be wholly interrupted each time it passes an aperture, the entire current flowing successively in the coils 50, 51 and 52. Thealternating current output of the device will therefore vary between zero and a maximum, the direct current output in the phase 50 also being modulated in an opposite manner. r

It will be seen also that complete modulation of the output of thefirst tube is not necessary in order to secure complete modulation of the second. The diameter of the path of the beam is directly proportional to the defiecting current, and this current need only varya relatively small per cent inorder to move the path-from theportion 21 of the anode out 'to the'position where complete interruption takes place. Since complete modulation is frequently desirable, and since it is dimcult to secure completemodulation without serious distortion in'using ordinary amplifying tubes, this invention offers a means of increasing the percentage of modulation at the same time that the frequency is multiplied.

Where a single phase current is desired in the output of the final stage, the tube 4'7 may be replaced by one of the type shown in Figure 3, the connectionbeing made at the line A-B in the first and third figures. The three deflecting coils 25, 26 and 2'? and their tuning condensers 34 are the same as before. The tube 47' is similar to the tube 47 in all respects except in its anode construction, only two anodes 65 and 66 being circuit of the tubecomprises a 7 of origin of each of said waves which is provided with a central tap connectingby a lead 69 to the anode source 12. The'work coil '70 tuned to the output frequency by a condenser 71. This may be used to supply an antenna '72 of conventional type. I

It will be understood that the tuning condenser 71 may be connected across the primary coil 6'7, if desired, or thatboth primary and secondary coils may be tuned, these details lying within the realm of ordinary radio design. 2

Modulation of'the single phase output of the coil 47f occurs in precisely the same way as modulation of the three-phase output ofthe tube 4'7, the dotted circles 60, 61 and62 showing the extreme positions and the mean position of the trace of the beam for complete modulation.

For either single phase or polyphase output the normal path of the beam should be in the posi ,tion shown by the circles 61 and 61". This gives normal unmodulated output. Deflecting the beam in either direction then decreases or increases the A. C. component to, modulate the wave. v

I claim:

1. The method of modulating the output of an alternating current generator comprising a cathode ray tube having an anode provided with a plurality of circularly arranged openings therein and means for deflecting a beam of rays from said cathode in a substantially circular path 7 across said openings, which comprises varying the diameter of said circular path at a modulating frequency to vary the proportion of said beam intermittently passing through said openings.

2. The method of modulating the output'of an alternating current generator comprising a cathode ray tube having an anode provided with a plurality of circularly arranged openings therein and means for-establishing a polyphase field for deflecting a beam of rays from said cathode in a substantially circular path across said openings, which comprises modulating said'fleld to vary the diameter of said path, thereby varying the proportion of said beam intermittently passing through said openings.

3. The method of producing a rotary polarized modulated radiouwave which comprises generating a beam of cathode rays, passing said beam through a polyphase field to deflect it in a circular path, modulating said field to vary the diameter of said path, diverting the electron flow comprising said beam into aplurality of paths in fixed succession, varying theproportion I of the electron flow thus diverted in proportion to the path diameter, and utilizing the current in each path to excite a radio wave, the locus being so spaced that the resultant of said Waves may be represented by a rotating vector advancing in space.

4. The method of producing a modulated alternating current which comprises generating a beam of cathode rays, passing said beam through a polyphase field todivert'the beam into a substantially circular path, modulating said tion corresponding to one field to vary the diameter of said path, and 'intermittently diverting a portion of said beam proportional to the path diameter- 5. 1%. modulating and frequency multiplying system comprising means for generating a beam of cathode rays, means for deflecting said rays at a predetermined frequency, an anode positioned to intercept said beam and having a porpath of deflection of the beam and having spaced openings therein and anotherportio-n Without openings and corresponding to another path of deflection, and

means for varying the position of the'beam between'said paths of deflection at a modulating frequency to 'modulate the current flowingito said anode through said beam.

6. A modulator and frequency multiplier comprising means for generating a beam of cathode rays, an'anode positioned to receive said beam and havinga plurality of circularly spaced openings therein and a circular portion without openings, means for establishing a polyphase field for deflecting said beam in a circular path, and means for modulating said field .to deflect said path between the'portions of the anode with and without openings; 1

7. A generator of modulated alternating current comprising a source of rality of anodes positioned to receive said rays at least one of said anodes comprising spaced segments, means for deflecting said rays in a cathode rays, 2, pluplurality of paths, one of said paths falling wholly upon one of said anodes, and another of said paths falling alternately and equally upon'each of said anodes, and means for varying the deflection of the rays between said paths frequency upon each of said anodes in succession, whereby the current in said branch circuits varies between a direct current flowing in a single branch circuit, and a pulsating direct current flowing equally in all of the branch circuits.

9. A generator of modulatedalternating current comprising a vacuum tube, an electron emitting cathode mountedwithin the tube, an anode positioned within the tube to receive electrons from said cathode and having a plurality of circularly arranged openings therein, a second anode positioned to receive e ectrons passing through said openings, means for deflecting said electrons in a path across said openings, and means for varying the deflection at signal path which does not traverse said openings.

10. A generator of modulated alternating current comprising a vacuum tube, an electron emitting cathode mounted within the tube, an anode positioned within the tube to receive electrons from said cathode and having a plurality of circularly arranged openings therein, a second anode positioned to receive electrons passing through said openings, a plurality of coils arranged around said tube and connected to form a polyphase circuit, means for supplying polyphase current to said coils to establish therewitha rotatfrequency into a 1 ing magnetic field Within the tube, and means for modulating said polyphase current to vary the deflection of electrons passing through said field from a path traversing said openings to a path not traversing said openings. 11. A generator of modulated alternating current comprising a vacuum tube, an'electron emitting cathode mounted within the tube, an anode positioned Within the tube to receive electrons rom said cathode and having a plurality of circularly arranged openings therein, means for de fleeting said electrons in a path traversing all of said openings, a plurality of additional anodes positioned successively to receive said electrons as their path traverses said openings, means for varying the deflection of said electrons at signal frequency into a path which does not traverse said openings, and a polyphase output circuit connected to said anodes.

. 12. A generator of modulated alternating current comprising a vacuum tube, an electron emitting cathode-(mounted within the tube, an anode positioned within the tube to receive electrons from said cathode and having a plurality of circularly arranged openings therein, means for defleeting said electrons in a path traversing all of said openings, a plurality of additional. anodes positioned successively to receive said electrons as their path traverses said openings, means for varying the deflection of said electrons at signal frequency into a path which does not traverse said openings, a polyphase output circuit connected to said anodes, and a polyphase radiating system connected to said output circuit. 13. A modulator and frequency multiplier comprising means for generating a beam of cathode rays, a segmented anode positioned in the path of said beam, means for deflecting said beam across said segments, and means for varying the deflection path of said beam at a modulating frequency to vary the proportion thereof falling on said segments. R 1a. A modulator and frequency multiplier com prising means for generating a beam of cathode rays, a circular anode having a segmented portion positioned in the path of said rays, means for deflecting said beam over said anode in a substantially circular path, and means for varying the diameter of said path at a modulating frequency to vary the proportion of said beam falling on the segmented portion of said anode.

RALPH M. HEINTZ. 

